Systems and methods for missed breath detection and indication

ABSTRACT

This disclosure describes improved systems and methods for displaying respiratory data to a clinician in a ventilatory system. Respiratory data may be displayed by any number of suitable means, for example, via appropriate graphs, diagrams, charts, waveforms, and other graphic displays. The disclosure describes novel systems and methods for determining and displaying ineffective patient inspiratory or expiratory efforts or missed breaths in a manner easily deciphered by a clinician.

INTRODUCTION

A ventilator is a device that mechanically helps patients breathe byreplacing some or all of the muscular effort required to inflate anddeflate the lungs. During respiration, the ventilator may be configuredto present various graphs, charts, and other displays indicative of thephysical condition of the patient and the respiratory treatmentprovided. The ventilatory displays may be further designed to presentrelevant clinical information to a practitioner in an efficient andorderly manner.

Missed Breath Detection and Indication

This disclosure describes improved systems and methods for displayingrespiratory data to a clinician in a ventilatory system. Respiratorydata may be displayed by any number of suitable means, for example, viaappropriate graphs, diagrams, charts, waveforms, and other graphicdisplays. The disclosure describes novel systems and methods fordetermining and displaying ineffective patient inspiratory or expiratoryefforts or missed breaths in a manner easily deciphered by a clinician.

In part, this disclosure describes a method for determining missedbreaths. The method includes:

a) monitoring respiratory data with at least one sensor;

b) analyzing the respiratory data with a first trigger detectionapplication and a second trigger detection application;

c) detecting patient inspiratory efforts with the first triggerdetection application and the second trigger detection application;

d) calculating a missed breaths metric based on detected patientinspiratory efforts by the first trigger detection application anddetected patient inspiratory efforts by the second trigger detectionapplication; and

e) displaying a missed breath indicator based on the missed breathsmetric.

Yet another aspect of this disclosure describes a medical ventilatorincluding:

a) at least one display device;

b) a missed breath module that determines missed breaths based on afirst trigger detection application;

c) a ventilation module that determines ventilation of a patient basedon a second trigger detection application; and

d) at least one memory, communicatively coupled to the at least oneprocessor and containing instructions that, when executed by a processorof the ventilatory system, provide a graphical user interface on the atleast one display, comprising a missed breath indicator.

The disclosure further describes a computer-readable medium havingcomputer-executable instructions for performing a method implemented bya ventilator for determining missed breaths, the method includes:

a) repeatedly monitoring respiratory data with at least one sensor;

b) repeatedly analyzing the respiratory data with a first triggerdetection application and a second trigger detection application;

c) repeatedly detecting patient inspiratory efforts with the firsttrigger detection application and the second trigger detectionapplication;

d) repeatedly calculating a missed breaths metric based on the resultsof the detection operation; and

e) repeatedly displaying a missed breath indicator based on the missedbreaths metric.

The disclosure also describes a medical ventilator system, includingmeans for monitoring respiratory data with at least one sensor, meansfor analyzing the respiratory data with a first trigger detectionapplication and a second trigger detection application, means fordetecting patient inspiratory efforts with the first trigger detectionapplication and the second trigger detection application, means forcalculating a missed breaths metric based on the results of thedetection operation, and means for displaying a missed breath indicatorbased on the missed breaths metric.

These and various other features as well as advantages whichcharacterize the systems and methods described herein will be apparentfrom a reading of the following detailed description and a review of theassociated drawings. Additional features are set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the technology. Thebenefits and features of the technology will be realized and attained bythe structure particularly pointed out in the written description andclaims hereof as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawing figures, which form a part of this application,are illustrative of embodiments, systems, and methods described belowand are not meant to limit the scope of the invention in any manner,which scope shall be based on the claims appended hereto.

FIG. 1 is a diagram illustrating an embodiment of an exemplaryventilator connected to a human patient.

FIG. 2 is a block diagram illustrating an embodiment of a ventilatorysystem having a graphical user interface for displaying respiratorydata.

FIG. 3 is a flow diagram illustrating an embodiment of a method forventilating a patient on a ventilator having a graphical user interfacefor displaying respiratory data.

FIG. 4 illustrates an embodiment of a graphical user interface fordisplaying a plurality of graphical representations of respiratory data,a delivered breath indicator, and a missed breath indicator.

FIG. 5 is a flow diagram illustrating an embodiment of a method fordisplaying and/or updating the display of a missed breath indicator.

FIG. 6 is a flow diagram illustrating an embodiment of a method fordisplaying and/or updating the display of a missed breath indicator.

DETAILED DESCRIPTION

Although the techniques introduced above and discussed in detail belowmay be implemented for a variety of medical devices, the presentdisclosure will discuss the implementation of these techniques in thecontext of a medical ventilator for use in providing ventilation supportto a human patient. The reader will understand that the technologydescribed in the context of a medical ventilator for human patientscould be adapted for use with other systems such as ventilators fornon-human patients, general gas transport systems, and other therapeuticequipment having graphical user interfaces for displaying data.

Medical ventilators are used to provide a breathing gas to a patient whomay otherwise be unable to breathe sufficiently. In modern medicalfacilities, pressurized air and oxygen sources are often available fromwall outlets. Accordingly, ventilators may provide pressure regulatingvalves (or regulators) connected to centralized sources of pressurizedair and pressurized oxygen. The regulating valves function to regulateflow so that respiratory gas having a desired concentration of oxygen issupplied to the patient at desired pressures and rates. Ventilatorscapable of operating independently of external sources of pressurizedair are also available.

In the medical device field, “patient effort” is a term that can be usedto describe many different patient parameters. To be clear, for thepurposes of this document, the term “patient effort” shall be usedherein to mean a patient's spontaneous attempt to initiate aninspiration or an exhalation as determined by an analysis of pressure,flow, volume, etc. measured by the ventilator. For example, a drop inpressure of greater than a threshold amount may be detected andidentified as a single effort of the patient to initiate an inspiration.At time, the phrase “patient inspiratory effort” or “patient expiratoryeffort” will be used instead of patient effort to remind the reader thatwhat is meant is an attempt by the patient to change the phase ofrespiratory cycle.

A recent study suggests that clinicians are able to detect less thanone-third of patient efforts that do not result in the delivery of abreath, or missed breaths.¹ Further, this study has shown that the rateof correct detection decreases as the prevalence of missed breathsincreases. Considering that missed breaths may occur in up to 80% ofmechanically ventilated patients, systems and methods for displayingmissed breaths are needed. While operating a ventilator on aspontaneously breathing patient, it is desirable to limit, or preferablyeliminate, patient efforts that do not result in the delivery of abreath. Hereinafter, patient efforts that do not result in the deliveryof a breath shall be referred to as “ineffective patient efforts” or“ineffective triggers”. In addition, patient inspiratory efforts that donot result in the delivery of a breath by the ventilator may also bereferred to as “missed breaths”. ¹ Colombo, D., Cammarota, G., Alemani,M., Carenzo, L., Barra, F., Vaschetto, R., et al. (2011). Efficacy ofventilator waveforms observation in detecting patient-ventilatorasynchrony. Critical Care Medicine, p. 3.

This disclosure describes systems and methods for displaying respiratorydata to a clinician in a ventilatory system. Specifically, the systemsand methods disclosed herein determine and/or display ineffectivepatient efforts.

FIG. 1 is a diagram illustrating an embodiment of an exemplaryventilator 100 connected to a human patient 150. The ventilator 100includes a pneumatic system 102 (also referred to as a pressuregenerating system 102) for circulating breathing gases to and from thepatient 150 via a ventilation tubing system 130, which couples thepatient to the pneumatic system via an invasive patient interface.

The ventilation tubing system 130 may be a two-limb (shown) or aone-limb circuit for carrying gas to and from the patient 150. In atwo-limb embodiment as shown, a fitting, typically referred to as a“wye-fitting” 170, may be provided to couple the patient interface to aninspiratory limb 132 and an expiratory limb 134 of the ventilationtubing system 130.

The pneumatic system 102 may be configured in a variety of ways. In thepresent example, the system 102 includes an expiratory module 108coupled with the expiratory limb 134 and an inspiratory module 104coupled with the inspiratory limb 132. A compressor 106 or othersource(s) of pressurized gases (e.g., air, oxygen, and/or helium) iscoupled with an inspiratory module 104 to provide a gas source forventilatory support via the inspiratory limb 132. A missed breath module109 is coupled with the inspiratory module 104 and the expiratory module108 to detect when a missed breath occurs and is described in moredetail in FIG. 2 below.

The pneumatic system 102 may include a variety of other components,including sources for pressurized air and/or oxygen, mixing modules,valves, sensors, tubing, accumulators, filters, etc. A controller 110 isoperatively coupled with the pneumatic system 102, signal measurementand acquisition systems, and an operator interface 120 that may enablean operator to interact with the ventilator 100 (e.g., change ventilatorsettings, select operational modes, view monitored parameters, etc.).The controller 110 may include memory 112, one or more processors 116,storage 114, and/or other components of the type commonly found incommand and control computing devices.

The memory 112 is computer-readable storage media that stores softwarethat is executed by the processor 116 and which controls the operationof the ventilator 100. The memory may be transitory or non-transitory.In an embodiment, the memory 112 includes one or more solid-statestorage devices such as flash memory chips. In an alternativeembodiment, the memory 112 may be mass storage connected to theprocessor 116 through a mass storage controller (not shown) and acommunications bus (not shown). Although the description ofcomputer-readable media contained herein refers to a solid-statestorage, it should be appreciated by those skilled in the art thatcomputer-readable storage media can be any available media that can beaccessed by the processor 116. Computer-readable storage media includesvolatile and non-volatile, removable and non-removable media implementedin any method or technology for storage of information such ascomputer-readable instructions, data structures, program modules orother data. Computer-readable storage media includes, but is not limitedto, RAM, ROM, EPROM, EEPROM, flash memory or other solid state memorytechnology, CD-ROM, DVD, or other optical storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other medium which can be used to store the desired informationand which can be accessed by the computer.

As described in more detail below, the controller 110 may monitor thepneumatic system 102 in order to evaluate the condition of the patientand to ensure proper functioning of the ventilator. The specificmonitoring may be based on inputs received from the pneumatic system 102and sensors, operator interface 120, and/or other components of theventilator. In the depicted example, operator interface includes adisplay 122 that is touch-sensitive, enabling the display to serve bothas an input and output device.

FIG. 2 is a block diagram illustrating an embodiment of a ventilatorysystem 200 having a graphical user interface for displaying respiratorydata.

A ventilator 202 includes a display module 204, memory 208, one or moreprocessors 206, user interface 210, monitor modules 216-222, timemonitor module 224, graphics module 226, and ventilation module 212. Theventilation module 212 further includes a missed breath module 211. Themissed breath module 211 in system 200 is the same as the missed breathmodule 109 described in the system 100 above. The memory 208 is definedas described above for the memory 112 in FIG. 1. Similarly, the one ormore processors 206 are defined as described above for the one or moreprocessors 116. The processors 206 may further be configured with aclock whereby elapsed time may be monitored by the system 200.Alternatively, a time monitor module 224 may be provided for monitoringtime and associating a temporal element with the various data collectedby the monitoring modules 216-222.

The ventilation module 212 oversees ventilation delivered to a patientaccording to the ventilator settings prescribed for the patient. Theventilator settings are determined by a selected or predeterminedventilation mode and/or breath type. The ventilation module 212 deliverspressure and/or volume into a ventilatory circuit (depending on whetherthe ventilator is configured for pressure or volume controlleddelivery), and thereby into a patient's lungs, based on the breath typeand/or mode. Spontaneous breath types are referred to herein as “triggerdetection applications,” since trigger detection applications requiredetection of patient effort in order to determine when to deliver abreath to the patient. The trigger detection applications include knownspontaneous breath types, such as but are not limited to ProportionalAssist Ventilation (PAV), Volume Ventilation Plus (VV+), I:E SYNC,Pressure Support (PS), Volume Support (VS), Assist Control (AC), VolumeControl (VC), Pressure Control (PC), Airway Pressure Release Ventilation(APRV), Continuous Positive Airway Pressure (CPAP), and BiLevel PositiveAirway Pressure (BPAP). As discussed above, the trigger detectionapplications trigger the delivery of a breath when a patient effort isdetected. While the methods for determining patient effort vary based onthe trigger detection application used, in some embodiments, the patienteffort is determined based on calculations involving monitored pressureand/or monitored flow. The ventilation module 212, and therefore thetrigger detection applications, is communicatively coupled to at leastone of the monitoring modules 216-222, the display module 204, thememory 208, the processor 206, the user interface 210, the graphicsmodule 226, the time monitor module 224, and any other suitablecomponent and/or module. For example, the trigger detection applicationmay determine when to trigger a breath based on monitored data receivedfrom the monitoring modules 216-222.

The ventilation module 212 further includes a missed breath module 211.The missed breath module 211 utilizes a trigger detection applicationthat detects patient efforts to determine when a patient desires adelivered breath. However, this trigger detection application does notever actually deliver any breath based on the detected patient effortsand is therefore referred to herein as running in the background or as a“background trigger detection application” (also referred to as a firsttrigger detection application). A trigger detection application utilizedto determine when to deliver the breaths to the patient duringventilation by the ventilator is referred to herein as the “activetrigger detection application” (also referred to as a second triggerdetection application). Accordingly, the background trigger detectionapplication and the active trigger detection application determine apatient effort by monitoring patient parameters from the monitoringmodules 216-222. In some embodiments, the background trigger detectionapplication determines patient efforts based on monitored intrapleuralpressure received from the intrapleural pressure (IP) monitoring module216.

The missed breath module 211 compares the detected patient efforts tothe delivered breaths by the ventilation module 212. For any detectedpatient effort that does not correlate with a delivered breath, themissed breath module 211 determines that the detected patient effort isan ineffective trigger effort by the patient. The missed breath module211 may store determined information or send determined information tothe display module 204, the processor 206, the memory 208, the userinterface 210, the time monitor module 224, the graphics module 226,and/or any other suitable component and/or module. The determinedinformation may include a single instance of an ineffective triggereffort by the patient, a sequential history of ineffective triggerefforts over a period of time (either predetermined or input by theclinician), or a rate of ineffective trigger efforts (for example thenumber of ineffective trigger efforts per minute) that may be averagedover a period of time that is predetermined or input by the clinician.

Further, for any detected patient effort that does correlate with adelivered breath, the missed breath module 211 determines the detectedpatient effort to be an effective trigger effort by the patient. Themissed breath module 211 may store determined information or senddetermined information to the display module 204, the processor 206, thememory 208, the user interface 210, the time monitor module 224, thegraphics module 226, and/or any other suitable component and/or module.The determined information may include a single instance of an effectivetrigger effort by the patient, a sequential history of effective triggerefforts over a period of time (either predetermined or input by theclinician), or a rate of effective trigger efforts (for example thenumber of effective trigger efforts per minute) that may be averagedover a period of time that is predetermined or input by the clinician.

The use of intrapleural pressure is an effective way to determinepatient effort. When a patient makes an effort to breath, the patient'sdiaphragm will contract, and decrease the intrapleural pressure in orderto draw air (or another substance) into the lungs. Because thecontraction of the diaphragm is the effect of patient effort theintrapleural pressure change is the first and most direct way todetermine patient effort, as a pressure/flow change will happensubsequently. Therefore a trigger detection application that usesintrapleural pressure is more sensitive to patient efforts than atrigger detection application that only uses pressure or flow. A triggerdetection application running in the background is a good way todetermine when missed breaths occur due to its inherent sensitivity.

A patient effort may be used to trigger one or more actions on the partof the ventilator, such as but not limited to a transition fromexhalation to inhalation (or from inhalation to exhalation). It shouldbe noted that ventilators depending on their mode of operation, maytrigger automatically and/or in response to a detected change in amonitored parameter such as but not limited to patient effort, pressure,and flow. In one embodiment a monitored flow signal is used to determinewhen patient effort occurs. A variety of signals, for example, can beused by a trigger detection application to determine when patient effortoccurs such as but not limited to patient airway pressure, lung flow,and intrapleural pressure. In an exemplary embodiment, the ventilatorutilizes multiple trigger detection applications simultaneously. A firsttrigger detection application is used to detect when patient effortoccurs, but the ventilator does not actively use the detected patienteffort to trigger one or more actions on the part of the ventilator. Inthis embodiment the first trigger detection application is used todetermine when a missed breath occurs. As used herein, the term “missedbreath” refers to a patient effort that does not trigger one or moreactions on the part of the ventilator, such as the delivery of a breath,the transition from inhalation to exhalation, or the transition fromexhalation to inhalation. The first trigger detection application usesintrapleural pressure to detect when a patient effort occurs. In thisembodiment, a second trigger detection application is used to determinewhen to trigger the ventilator. The second trigger detection applicationmay use any suitable current or future known triggering methods based onmonitored respiratory parameters such as but not limited to pressure andflow.

The display module 204 presents various input screens to a clinician,including but not limited to one or more graphics display screens, aswill be described further herein, for receiving clinician input and fordisplaying useful clinical data to the clinician. The display module 204is further configured to communicate with the user interface 210. Thedisplay module 204 may provide various windows, controls, and displayelements to the clinician via a graphical user interface (GUI) for inputand interface command operations. Thus, the user interface 210 mayaccept commands and input through the display module 204. The displaymodule 204 may also provide useful information in the form of variousrespiratory data regarding the physical condition of a patient and/orthe prescribed respiratory treatment. The useful information may bederived by the ventilator 202, based on data gathered from the variousmonitoring modules 216-222, and the useful information may be displayedto the clinician in the form of graphs, wave representations, piegraphs, text, symbols, prompts, graphics, lights, lines, indicators, orother suitable forms of graphic display. The display module 204 mayfurther be an interactive display, whereby the clinician may bothreceive and communicate information to the ventilator 202, as by atouch-activated display screen. Alternatively, the user interface 210may provide other suitable means of communication with the ventilator202, for instance by a keyboard or other suitable interactive device.

One or more graphics display screens provided by the display module 204may each display one or more graphic representations of respiratorydata, for example, graphical representations may include, inter cilia,pressure waveforms, volume waveforms, flow waveforms, flow curves,pressure-volume loops, flow-volume loops, text, symbols, prompts,graphics, lights, lines, cursors, interactive elements, indicators, orany other current or future known graphical representation suitable fordisplaying respiratory data. For instance, a volume waveform may depicttidal volume, i.e., the total volume of air inhaled and exhaled for onerespiratory cycle, over time. A pressure waveform may depict circuitpressure, as measured or derived, for each inspiration and expirationover time. A pressure-volume loop may be generated for each breath,inspiration represented as a positive curve and expiration representedas a negative curve completing a single loop. In some embodiments thegraphical representation is a respiratory rate as illustrated in FIG. 4.

In other embodiments, an indicator is displayed by the one or moregraphics display screens provided by the display module 204. Theindicator may be a missed breath or a delivered breath indicator. Themissed breath indicator displays data relating to a missed breath andthe delivered breath indicator displays data relating to a deliveredbreath. The indicators include as measured or derived, for each instanceof a delivered and/or missed breath, for total delivered and/or missedbreaths over a period of time, for a rate of delivered and/or missedbreaths, for a history of delivered and/or missed breaths, or for anycombination thereof. In some embodiments, the indicator is displayed ontop of or within the one or more graphical representations.

In some embodiments, the ventilator stores a sequential history of thegraphical representations and/or respiratory data, such as a missedbreath indicator and a delivered breath indicator. As described above,the graphics module 226, or another suitable component or module, mayarchive graphical representations and indicators according to time. Somegraphical representations and/or indicators may inherently include atime element, as with waveforms of respiratory data presented over time.Other graphical representations or indicators may be presented as afunction of a single respiratory cycle, or breath, such as a flow-volumeor a pressure-volume loop. The graphics module 226, or another suitablecomponent or module, may associate the respiratory data of the graphicalrepresentation and/or indicators with a time element. In thealternative, the monitoring modules 216-222 may associate therespiratory data with a time element, or time stamp, beforecommunicating data to the graphics module 226. In either case, graphicalrepresentations and/or indicators may be archived in sequential orderbased on time. In an embodiment, a cursor or indicator is displayed overa graphical representation of a respiratory signal such as, but notlimited to, pressure and flow, at an appropriate temporal location basedon when the delivered and/or missed breath occurred.

In an embodiment, a delivered and/or missed breath indicator isdisplayed as at least one of text, symbol, prompt, graphic, light, lineor by another suitable form of graphic display. In another embodiment,the missed breath and delivered breath indicator include the display ofa delivered and/or missed breath rate. The graphics module 226, oranother suitable component or module, may archive historical data, suchas indicators, which may be time-stamped, in sequential order over aparticular time period. This rate can be the number or an average of thenumber of delivered and/or missed breaths per time period, where thetime period can be predetermined, such as a minute, or input by theclinician. For example, the indicators may display the number ofdelivered and/or missed breaths in the last minute. The average can betaken from a predetermined or input number of values over apredetermined or input period of time. For example, the indicators mayfurther display a rate based on an average of the last five values whereeach value represents the number of delivered and/or missed breaths forthat minute. In an embodiment, the indicator may display a percentage orratio at least partially representative of the delivered and/or missedbreaths. For example, if the number of delivered breaths as well as thenumber of missed breaths are both known, then the indicator may displaya percentage or ratio of delivered and/or missed breaths per totalbreaths, where total breaths is the addition of missed breaths anddelivered breaths. In an embodiment, the indicators include a totalbreath indicator where the total breath indicator represents theaddition of missed breaths and delivered breaths. Additionally, anindicator such as but not limited to text, symbol, prompt, graphic,light, line, cursor, interactive element, or indicator may be displayedto represent that missed breaths are being monitored. Further, anindicator such as but not limited to text, symbol, prompt, graphic,light, line, cursor, interactive element, or indicator may be displayedto represent settings for monitoring missed breaths. In someembodiments, a prompt is displayed with adjustable elementsrepresentative of turning on and/or off the missed breath module 211 aswell as an inhalation and exhalation trigger values for missed breathmonitoring. In some embodiments, these indicators are selectable and/oradjusted by a clinician via the user interface.

Data may be collected and displayed according to any suitable method.Thus, a plurality of various graphical representations and/or indicatorsmay be provided, each graphical representation and/or indicatorcommunicating different useful information to the clinician. However,sometimes it may be useful for the clinician to compare the respiratorydata displayed if the respiratory data is displayed in a manner that iseasier for the clinician to understand, which increases the chance thatthe clinician will discover a missed breath and can decreasepatient-ventilator asynchrony by adjusting ventilator parameters.

The monitoring modules 216-222 operate to monitor the physical conditionof the patient in conjunction with the proper operation of theventilator 202. Although only a sampling of potential monitoring modulesare shown and described, any number of suitable monitoring modules maybe provided in keeping within the spirit of the present disclosure. Themonitoring modules 216-222 may communicate with the display module 204,the user interface 210, the graphics module 226, the missed breathmodule 211, the ventilation module 212, and/or other suitable modules orprocessors of the ventilator 202. Specifically, the monitoring modules216-222 may communicate with the graphics module 226 and/or the displaymodule 204 such that collected data regarding the physical condition ofthe patient and/or the prescribed ventilation may be displayed to theclinician.

The monitoring modules 216-222 may utilize one or more sensors to detectchanges in various physiological parameters. Specifically, the one ormore sensors may be placed in any suitable internal location, within theventilator itself, or in any suitable external location, within theventilatory circuitry or other devices communicatively coupled to theventilator 202. For example, sensors may be coupled to inspiratoryand/or expiratory modules for detecting changes in, for example, circuitpressure and flow. Additionally, the one or more sensors may be affixedto the ventilatory tubing or may be imbedded in the tubing itself.

An intrapleural pressure monitor module 216 monitors or estimatesintrapleural pressure. The term “intrapleural pressure,” as used herein,refers generally to the pressure exerted by the patient's diaphragm onthe cavity in the thorax that contains the lungs, or the pleural cavity,and should further represent estimates of the pressure and/or anyderivatives thereof. The intrapleural pressure monitor module 216 maymeasure intrapleural pressure according to any suitable method eitherknown or discovered in the future. Alternatively, the intrapleuralpressure monitor module 216 may derive intrapleural pressure readingsfrom other data and measurements according to mathematical operations orotherwise. For example, an algorithm that estimates how the patient'sintrapleural pressure is changing in real-time based on measuredpressure and flow may be used. In one embodiment, the algorithm utilizedmeasured pressure, inlet flow, and outlet flow to determine intrapleuralpressure is the algorithm described in U.S. patent application Ser. No.12/980,583 filed Dec. 29, 2010. U.S. patent application Ser. No.12/980,583 filed Dec. 29, 2010 is incorporated herein by reference inits entirety.

A pressure monitor module 218 monitors pressure within a ventilatorycircuit. The pressure monitor module 218 may measure pressure accordingto any suitable method either known or discovered in the future. Forexample, pressure transducers may be attached at various locations alongthe ventilatory circuit to detect changes in circuit pressure.Specifically, sensors may utilize optical or ultrasound techniques formeasuring changes in circuit pressure. Alternatively, the pressuremonitor module 218 may derive pressure readings from other data andmeasurements according to mathematical operations or otherwise.

A flow monitor module 220 monitors airflow within a ventilatory circuit,for example by utilizing sensors as described above for monitoringpressure. Inspiratory flow may be represented as a positive flow andexpiratory flow may be represented as a negative flow. Flow may bemeasured or derived by any suitable method either currently known ordisclosed in the future. Specifically, flow may be derived according tomathematical operations or measured at selected points along theventilatory circuit.

A volume monitor module 222 monitors the volume of air exchanged duringa respiratory cycle. The volume monitor module 222 may measure tidalvolume by any suitable method, or may derive volume according tomathematical equations based on measurements of pressure and/or flow,for example.

The display module 204 may be further configured to communicate with thegraphics module 226. The graphics module 226 may interact with thevarious monitoring modules 216-222 and may process data received fromthe monitoring modules 216-222 and the time module 224 to produce thevarious indicators and/or graphical representations displayed on thedisplay module 204. In some embodiments, the display module 204 furtherinteracts with the missed breath module 109. Alternatively, the graphicsmodule 226 may be configured with a clock for monitoring time withoutneed for an additional time module 224. The graphics module 226 may beconfigured to process data according to any suitable mathematical orgraphical means. For instance, the graphics module 226 may plot raw datareceived from one monitoring module versus raw data received fromanother monitoring module. Alternatively, the graphics module 226 maytransform raw data received from one or more monitoring modules byutilizing one or more mathematical operations, and may plot themathematically transformed data versus other raw data, versus othertransformed data, or versus a unit of time, for example. The graphicsmodule 226 may transform raw data and may plot transformed or raw datato produce any number of useful graphical representations and/orindicators as may be desired by the clinician. The graphics module 226may receive commands from the user interface 210 or may be preconfiguredto perform certain default operations and manipulations of data forgenerating useful graphical representations and/or indicators. Thegraphics module 226 may further be configured to continuously acceptdata from the various monitoring modules 216-222, the missed breathmodule 109, and/or from the user interface 210 such that the graphicalrepresentations and/or indicators displayed on the display module 204may be continuously updated and presented in real-time orquasi-real-time to the clinician.

Additionally, the graphics module 226 may be configured to storehistorical data associated with each graphical representation and/orindicator. The graphics module 226 may be in communication with the timemonitor module 224, or other clock feature provided by the ventilator202, such that data within each graphical representation and/orindicator is associated with a time stamp. Specifically, underlyingrespiratory data may be time-stamped as it is received from themonitoring modules 216-222. As graphical representations of therespiratory data are generated by the graphics module 226, a timeelement may be incorporated such that each position on a waveform orloop, for instance, is associated with a time element. The graphicsmodule 226 may archive time-stamped or non-time-stamped historical datain sequential order over a particular time period. Thereafter, aclinician may utilize a scroll feature to scroll through a history ofgraphical representations and/or indicators stored over the time period.The time period may represent any temporal period of interest to theclinician, for instance, an hour, a day, a week, or an entire treatmentperiod. Indeed, the ventilator may archive all data during a respiratorytreatment period unless the clinician instructs otherwise. In thealternative, the ventilator may archive data over a most recent period,perhaps the last day, in order to free memory for other ventilatoryfunctions.

In an embodiment, as a clinician utilizes the scroll feature, thegraphics module 226 may drill into the underlying historical data todetermine an associated time element, or may retrieve a time elementassociated with each stored graphical representation and/or indicator,in order to provide an appropriate graphical representation and/orindicators to the clinician based on a selected historical time. Forexample, the graphics module 226 may determine an appropriate historicalpressure waveform, an appropriate historical indicator, and anappropriate position on the appropriate pressure waveform associatedwith a selected historical time. The graphics module 226 may display acursor at the appropriate position on the appropriate pressure waveformand may display historical indicators, such as but not limited to missedbreath indicators, delivered breath indicators, and total breathindicators, within an appropriate range of the cursor. The graphicsmodule 226 may also be configured to simultaneously display cursors andhistorical indicators in corresponding locations on any other displayedgraphical representations based on the selected historical time. Asdescribed above, reference lines intersecting the cursors and the axesof the various graphical representations may also be provided, alongwith a plurality of boxed fields for highlighting specific respiratorydata associated with the selected historical time.

FIG. 3 is a flow diagram illustrating an embodiment of a method 300 forventilating a patient on a ventilator. In some embodiments, theventilator performing the method 300 is the ventilator 100 described inFIG. 1, having a graphical user interface for displaying respiratorydata. The method 300 includes a respiratory data display operation 304,an effort detection operation 306, an effective trigger determinationoperation 308, an update delivered breath indicator operation 310, andan update missed breath indicator operation 312.

A patient is ventilated with a ventilator. As illustrated, the method300 begins after the start of ventilation.

The method 300 includes the respiratory data display operation 304. Theventilator system during the respiratory data display operation 304determines at least one graphical representation of respiratory databased on the ventilation of the patient and displays the graphicalrepresentations. In one embodiment, the ventilator uses the display 122to perform the respiratory data display operation 304. The graphicalrepresentations may include a waveform, flow curve, pressure-volumeloop, flow-volume loop, text symbol, prompt, graphic, light, line,cursor, interactive element, and indicator. The graphical representationmay include collected data regarding the physical condition of thepatient. The graphical representation may be displayed to the clinicianin real-time, quasi-real-time, or historically. As described above, aventilator may provide numerous graphical representations of respiratorydata to a clinician during respiration of a patient. The graphicalrepresentation may be determined by the ventilator during therespiratory data display operation 304 based on monitored data. Theventilator may receive the monitored data from monitoring modules, suchas the monitoring modules 216-222 discussed in FIG. 2 above. Theventilator may store a sequential history of the graphicalrepresentations provided. The graphics module 226, or another suitablecomponent or module, may archive graphical representations according totime. Some graphical representations may inherently include a timeelement, as with waveforms of respiratory data presented over time.Other graphical representations may be presented as a function of asingle respiratory cycle, or breath, such as a flow-volume or apressure-volume loop. The graphics module 226, or another suitablecomponent or module, may associate the respiratory data of the graphicalrepresentation with a time element. In the alternative, the monitoringmodules 216-222 may associate the respiratory data with a time element,or time stamp, before communicating data to the graphics module 226. Ineither case, graphical representations may be archived in sequentialorder based on time.

It is understood by a person of skill in the art that the respiratorydata display operation 304 may be performed at any time and/orsimultaneously with any other operation in the method 300 that isperformed after the start of ventilation but before the performance ofthe display delivered breath indicator operation 310 and the displaymissed breath indicator operation 312.

The method 300 further includes the effort detection operation 306. Theventilator system during the effort detection operation 306 monitorspatient respiratory data and detects patient effort with an active and abackground trigger detection application. As used herein, the term“patient effort” refers to an effort exerted by the patient to inspireand/or exhale gases. As discussed above, a trigger detection applicationis a hardware or software application that determines when a patienteffort occurs based on a selected or predetermined spontaneous breathtype. The active trigger detection application may include ProportionalAssist Ventilation (PAV), Volume Ventilation Plus (VV+), I:E SYNC,Pressure Support (PS), Volume Support (VS), Assist Control (AC), VolumeControl (VC), Pressure Control (PC), Airway Pressure Release Ventilation(APRV), Continuous Positive Airway Pressure (CPAP), and BiLevel PositiveAirway Pressure (BPAP). The active trigger detection application maydetermine patient efforts based on monitoring respiratory parameterssuch as but not limited to pressure and flow. In one embodiment thebackground trigger detection application is I:E SYNC. In thisembodiment, the background trigger detection application determinespatient effort based on monitoring intrapleural pressure.

As illustrated, the method 300 includes the trigger determinationoperation 308. The ventilator during the trigger determination operation308 determines whether a detected patient effort was effective orineffective. The effective patient effort is determined based ondetected patient effort by the second trigger detection application. Inan embodiment, a patient effort detected by the second trigger detectionapplication that results in the delivery of a breath is determined to beeffective. In another embodiment, if a first patient effort detected bythe first trigger detection application correlates to a second patienteffort detected by the second trigger detection application, then thetwo detected patient efforts are considered to have been generated bythe same patient effort and is therefore determined effective. The firstpatient effort and the second patient effort may correlate if recordedat the same time or within a reasonable and expected time delay, such as3 seconds or less. This effective patient effort may result in thedelivery of a breath.

The ineffective trigger effort is determined based on detected patienteffort by the first trigger detection application not correlating withdetected patient effort by the second trigger detection application. Thefirst patient effort and the second patient effort may correlate ifrecorded at the same time or within a reasonable and expected timedelay, such as 3 seconds or less. If there is not any correlationbetween the first detected patient effort and the second detectedpatient effort, then the patient effort that was not used to trigger theventilator, in this case the first detected patient effort, isdetermined to be ineffective. Further, a missed breath is the directresult of an ineffective effort. In an embodiment, an equation ormathematical operation is used to determine if the first detectedpatient effort correlates with the second detected patient effort. In anembodiment, the first trigger detection application is running in thebackground, and not actively used to trigger the delivery of breaths tothe patient. Further, the second trigger detection application isactively working and is used to trigger the delivery of breaths to thepatient. In an embodiment, the first trigger detection applicationdetermines patient effort based at least in part on intrapleuralpressure.

If the detected patient effort is determined to be effective, the method300 will perform the update delivered breath indicator operation 310. Ifthe detected patient effort is determined to be ineffective, the method300 will perform the update missed breath indicator operation 312.

The method 300 further includes the update delivered breath indicatoroperation 310. The ventilator during the update delivered breathindicator operation 310 displays a delivered breath indicator for theeffective trigger effort on the graphical representation. In anembodiment, the ventilator during the update delivered breath indicatoroperation 310 updates the display of a delivered breath indicator thatwas previously displayed. The ventilator may store a sequential historyof the delivered breath indicators provided. As described above, thegraphics module 226, or another suitable component and/or module, mayarchive delivered breath indicators according to time, and may associatea time element with the delivered breath indicators. In an alternativeembodiment, the monitoring modules 216-222 associate the deliveredbreath indicators with a time element, or time stamp, beforecommunicating data to the graphics module 226. In either case, deliveredbreath indicators may be archived in sequential order based on time,resulting in an archived effective indicator. In an embodiment, thedelivered breath indicator is displayed on top of a graphicalrepresentation of a respiratory signal such as, but not limited to,pressure and flow, at an appropriate temporal location based on when thedelivered breath occurred. In an embodiment, a delivered breathindicator is displayed as at least one of text, symbol, prompt, graphic,light, line, cursor, interactive element, indicator, or by anothersuitable form of graphic display. In another embodiment the deliveredbreath indicator displays a delivered breath rate. This rate can be thenumber or an average of the number of delivered breaths per time period,where the time period can be predetermined, such as a minute, or inputby the clinician. For example, a delivered breath indicator displays thenumber of delivered breaths in the last minute. The average can be takenfrom a predetermined or input number of values over a predetermined orinput period of time. For example, a delivered breath indicator displaysa rate based on an average of the last five values where each valuerepresents the number of delivered breaths for that minute. In anembodiment, a delivered breath indicator displays a percentage or ratioat least partially representative of the delivered breaths. For example,if the number of delivered breaths as well as the number of missedbreaths are both known then a delivered breath indicator representing apercentage or ratio of delivered breaths per total breaths may bedisplayed where total breaths is the addition of missed breaths anddelivered breaths. Indeed, data may be collected and displayed accordingto any suitable method.

The method 300 further includes the update missed breath indicatoroperation 312. The ventilator during the update missed breath indicatoroperation 312 displays a missed breath indicator for the ineffectivetrigger effort on the graphical representation. In an embodiment, theventilator during the update missed breath indicator operation 312updates the display of a missed breath indicator that was previouslydisplayed. The ventilator may store a sequential history of the missedbreath indicators provided. The missed breath module 211, or anothersuitable component and/or module, may archive missed breath indicatorsaccording to time, and may associate a time element with the missedbreath indicators. In the alternative, the monitoring modules 216-222may associate the missed breath indicators with a time element, or timestamp, before communicating data to the graphics module 226 and/or themissed breath module 211. In either case, missed breath indicators maybe archived in sequential order based on time, resulting in an archivedineffective indicator. In an embodiment missed breath indicators as wellas delivered breath indicators may be archived in sequential order basedon time, resulting in an archived total indicator. In an embodiment, themissed breath indicator is displayed on top of a graphicalrepresentation of a respiratory signal such as, but not limited to,pressure and flow, at an appropriate temporal location based on when themissed breath occurred. In an embodiment, a missed breath is displayedas at least one of text, symbol, prompt, graphic, light, line, cursor,interactive element, indicator, or by another suitable form of graphicdisplay. In another embodiment the missed breath indicator displays amissed breath rate. This rate can be the number or an average of thenumber of missed breaths per time period, where the time period can bepredetermined, such as a minute, or input by the clinician. For example,a missed breath indicator displays the number of missed breaths in thelast minute. The average can be taken from a predetermined or inputnumber of values over a predetermined or input period of time. Forexample, a missed breath indicator displays a rate based on an averageof the last five values where each value represents the number of missedbreaths for that minute. In an embodiment, a missed breath indicatordisplays a percentage or ratio at least partially representative of themissed breaths. For example, if the number of delivered breaths as wellas the number of missed breaths are both known then a missed breathindicator representing a percentage or ratio of missed breaths per totalbreaths may be displayed where total breaths is the addition of missedbreaths and delivered breaths. In an embodiment, the missed breathindicator displays a total breath indicator where the total breathindicator at least partially represents the total breaths, where thetotal breaths is the addition of missed breaths and delivered breaths.Additionally, a missed breath indicator may be displayed to representthat missed breaths are being monitored. Further, a missed breathindicator may be displayed to represent settings for monitoring missedbreaths. For example, a missed breath indicator displays a prompt withadjustable elements representative of turning on and/or off the missedbreath monitoring as well as inhalation and exhalation trigger valuesfor missed breath monitoring using the first trigger detectionapplication. Indeed, data may be collected and displayed according toany suitable method.

It is understood by a person of skill in the art that the updatedelivered breath indicator operation 310 and the update missed breathindicator operation 312 may be performed in any order and/orsimultaneously. In one embodiment, the update delivered breath indicatoroperation 310 and/or the update missed breath indicator operation 312are performed in real-time or quasi-real-time.

In an embodiment, the method 300 repeats and/or is performed at leastonce during each breath cycle.

FIG. 4 illustrates an embodiment of a graphical user interface (GUI) 400for displaying a plurality of graphical representations of respiratorydata, a delivered breath indicator, and a missed breath indicator.Specifically, FIG. 4 illustrates an embodiment of a missed breathdisplay screen wherein a clinician may initiate a missed breathmonitoring mode and thereafter may simultaneously view a plurality ofgraphical representations and missed breath indicators corresponding tomissed breaths.

The disclosed embodiment of the graphical user interface 400 provides aplurality of graphical representations of respiratory data to aclinician. Graphical representations may include, inter cilia, pressurewaveforms, volume waveforms, flow waveforms, flow curves,pressure-volume loops, flow-volume loops, text, symbols, prompts,graphics, lights, lines, cursors, interactive elements, indicators, orany other current or future known graphical representation suitable forthe GUI 400. Specifically, the GUI 400 includes, for example, a pressurewaveform (graphical representation 402), a flow waveform (graphicalrepresentation 404), a historical delivered breath indicator (deliveredbreath indicator 406), a delivered breath indicator (delivered breathindicator 408), a missed breath indicator (missed breath indicator 410),a historical missed breath indicator (missed breath indicator 412), amissed breath cursor (missed breath indicator 414), a delivered breathcursor (delivered breath indicator 416), and a monitoring mode settingsbox (missed breath indicator 418).

The pressure waveform 402 may display circuit pressure in cm H₂O overtime (for example, over seconds, s). As shown, the pressure waveform 402illustrates two distinct peaks in circuit pressure, corresponding to theinspiratory phases of two respiratory cycles, or breaths. The flowwaveform 404 may display flow in liters (L) over time (for example, overminutes, min). As shown, the flow waveform 404 illustrates inspiratoryflow as a positive curve, and expiratory flow as a negative curve. Twodistinct respiratory cycles or breaths, each including a positiveinspiratory phase and a negative expiratory phase, are illustrated inthe flow waveform 404.

As described previously, the delivered breath indicator 408 may beprovided to display the rate of delivered breaths over time (forexample, over minutes, min) for a period of time. As shown, thedelivered breath indicator 408 is a floating indicator over an axis ofbreaths per minute. The delivered breath indicator 408 may be text,symbol, prompt, graphic, light, line, cursor, interactive element,indicator, or any display element suitable to display a rate ofdelivered breaths over time. In an embodiment, the period of time ispredetermined or input by a clinician. For example, if a clinician wantsto see the effect of changing settings on patient-ventilator synchrony,the clinician can set the historical delivered breath indicator 406 asthe current delivered breath indicator 408. Then the clinician canchange ventilation settings and observe how the change in settingsaffects the delivered breath indicator 408. This observation may givethe clinician insight as to how effective the change in ventilationsettings was to reduce patient-ventilator asynchrony. In an embodiment,the delivered breath indicator 408 includes a numeric value and/or textused to display delivered breaths over time for a period of time. Forexample, at least one of a number of delivered breaths over a period oftime, such as the last minute, and a percentage or ratio of how many ofthe total breaths over a period of time, such as the last minute, weredelivered where total breaths is the addition of missed breaths anddelivered breaths.

As described previously the missed breath indicator 410 may be providedto display the rate of missed breaths over time (for example, overminutes, min) for a period of time. As shown, the missed breathindicator 410 is a floating indicator over an axis of breaths perminute. The missed breath indicator 410 may be text, symbol, prompt,graphic, light, line, cursor, interactive element, indicator, or anydisplay element suitable to display a rate of missed breaths over time.In an embodiment, the period of time is predetermined or input by aclinician. For example, if a clinician wants to see the effect ofchanging settings on patient-ventilator synchrony, the clinician can setthe historical missed breath indicator 412 as the current missed breathindicator 410. Then the clinician can change ventilation settings andobserve how the change in settings affects the missed breath indicator410. This observation may give the clinician insight as to how effectivethe change in ventilation settings was to reduce patient-ventilatorasynchrony. In an embodiment, the missed breath indicator 410 includes anumeric value and/or text used to display missed breaths over time for aperiod of time. For example, at least one of a number of missed breathsover a period of time, such as the last minute, and a percentage orratio of how many of the total breaths over a period of time, such asthe last minute, were missed where total breaths is the addition ofmissed breaths and delivered breaths.

As previously described, the historical delivered breath indicator 406may be provided to display the rate of delivered breaths over time (forexample, over minutes, min) for a historical archived period of time. Asshown, the historical delivered breath indicator 406 is a floatingindicator over an axis of breaths per minute. In an embodiment, thehistorical archived period of time is predetermined or input by aclinician. For example, if a clinician wants to see the effect ofchanging settings on patient-ventilator synchrony, the clinician can setthe historical delivered breath indicator 406 as the current deliveredbreath indicator 408. Then the clinician can change ventilation settingsand observe how the change in settings affects the delivered breathindicator 408. This observation may give the clinician insight as to howeffective the change in ventilation settings was to reducepatient-ventilator asynchrony. In an embodiment, the historicaldelivered breath indicator 406 includes a numeric value and/or text usedto display delivered breaths over time for a historical archived periodof time. For example, at least one of a number of delivered breaths overa period of time, such as a minute, and a percentage or ratio of howmany of the total breaths over a period of time, such as a minute, weredelivered where total breaths is the addition of missed breaths anddelivered breaths.

As previously described, the historical missed breath indicator 412displays the rate of total breaths over time (for example, over minutes,min) for a historical archived period of time, where total breaths isthe addition of delivered breaths and missed breaths. In anotherembodiment, the historical missed breath indicator 412 displays the rateof missed breaths over time (for example, over minutes, min) for ahistorical archived period of time. As shown, the historical missedbreath indicator 412 is a floating indicator over an axis of breaths perminute. Further, the historical missed breath indicator 412 is of ashape that will form a distinguishable shape, which may or may not bedifferent, when representing the same value on the axis as thehistorical delivered breath indicator 406. In an embodiment, thehistorical archived period of time is predetermined or input by aclinician. For example, if a clinician wants to see the effect ofchanging settings on patient-ventilator synchrony, the clinician can setthe historical missed breath indicator 412 as the current missed breathindicator 410. Then the clinician can change ventilation settings andobserve how the change in settings affects the missed breath indicator410. This observation may give the clinician insight as to how effectivethe change in ventilation settings was to reduce patient-ventilatorasynchrony. In an embodiment, the historical missed breath indicator 412includes a numeric value and/or text used to display missed breaths overtime for a historical archived period of time. For example, at least oneof a number of missed breaths over a period of time, such as a minute,and a percentage or ratio of how many of the total breaths over a periodof time, such as a minute, were missed where total breaths is theaddition of missed breaths and delivered breaths. It should be notedthat in the depicted embodiment the axis label “Respiratory RateSynchrony Indicator” represents a missed breath indicator used todisplay that a mode, such as the missed breath module 211 or triggerdetection applications as described above, is running in the backgroundto determine when missed breaths occur.

The GUI 400 further includes the missed breath cursor 414. The missedbreath cursor 414 is a specific type of missed breath indicator 410 thatis provided to display relative to another graphical representation, forexample the pressure waveform 402 and/or the flow waveform 404, when amissed breath occurred. As described previously with reference to thegraphics module 226, missed breath indicators may be time-stamped, orotherwise associated with a time element, when respiratory data isreceived by the monitoring modules 216-222 or the missed breath module211. Alternatively, a time element may be associated with therespiratory data when a graphical representation and/or indicator isgenerated by the graphics module 226 or missed breath module 211, forexample. In either case, when a clinician utilizes a cursor mode toscroll back into historical data, the graphics module 226, or otherretrieval module (not shown), may determine appropriate respiratory datacorresponding to the scroll time. The appropriate respiratory data maythen be displayed as the missed breath cursor 414. As shown, the missedbreath cursor 414 is a cursor displayed at the correct temporal locationover the pressure waveform 402 and the flow waveform 404, and representsan occurrence of a missed breath. Further, the missed breath cursor 414as shown is of a shape that will form a distinguishable shape, which mayor may not be different, when located at the same or similar temporallocation as the delivered breath cursor 416. In an embodiment, a patienteffort detected using the missed breath module 211 or the triggerdetection applications as described above while running in thebackground to detect missed breaths is displayed using the missed breathcursor 414. As shown, the most recent breath (the cursor furthest to theright of the pressure 402 and flow waveforms 404) was triggered by apatient effort that was detected by both a mode running in thebackground to detect missed breaths and a mode used to trigger theventilator, and therefore the cursor forms a different shape, in thiscase a diamond as opposed to a triangle, which can be interpreted by aclinician as a synchronous patient effort, or a patient effort thatdirectly resulted in the delivery of a breath from the ventilator.

The GUI 400 further includes the delivered breath cursor 416. Thedelivered breath cursor 416 is a specific type of missed breathindicator 410 that is provided to display relative to another graphicalrepresentation, for example the pressure waveform 402 and/or the flowwaveform 404, when a delivered breath occurred. As described previouslywith reference to the graphics module 226, delivered breath indicatorsmay be time-stamped, or otherwise associated with a time element, whenrespiratory data is received by the monitoring modules 216-222.Alternatively, a time element may be associated with the respiratorydata when a graphical representation is generated by the graphics module226, for example. In either case, when a clinician utilizes a cursormode to scroll back into historical data, the graphics module 226, orother retrieval module (not shown), may determine appropriaterespiratory data corresponding to the scroll time. The appropriaterespiratory data may then be displayed as the delivered breath cursor416. As shown, the delivered breath cursor 416 is a cursor displayed atthe correct temporal location over the pressure waveform 402 and theflow waveform 404, and represents an occurrence of a delivered breath.Further, the delivered breath cursor 416 as shown is of a shape thatwill form a distinguishable shape, which may or may not be different,when located at the same or similar temporal location as the missedbreath cursor 414. In an embodiment, a patient effort detected using themonitoring modules 216-222 or the trigger detection applications asdescribed above while running in the foreground to detect patient effortor other respiratory data used to trigger the delivery of a breath isdisplayed using the delivered breath cursor 416.

The GUI 400 further includes the monitoring mode settings 418. Themonitoring mode settings 418 may be provided to display and/or adjustone or more settings relating to the trigger detection applicationrunning in the background to detect missed breaths. As shown themonitoring mode settings 418 include an option for turning the missedbreath monitoring on or off, a setting to adjust the inhalation triggersensitivity level of the background trigger detection application, asetting to adjust the exhalation trigger sensitivity level of thebackground trigger detection application, and an option to close, or notdisplay, the monitoring mode settings 418.

The disclosed windows and elements of the GUI 400 may be arranged in anysuitable order or configuration such that information may becommunicated to the clinician in an efficient and orderly manner.Windows disclosed in the illustrated embodiment of the GUI 400 may beconfigured with elements for accessing alternative graphical displayscreens as may be provided by the ventilator. Disclosed windows andelements are not to be understood as an exclusive array, as any numberof similar suitable windows and elements may be displayed for theclinician within the spirit of the present disclosure. Further, thedisclosed windows and elements are not to be understood as a necessaryarray, as any number of the disclosed windows and elements may beappropriately replaced by other suitable windows and elements withoutdeparting from the spirit of the present disclosure. The illustratedembodiment of the GUI 400 is provided as an example only, includingpotentially useful windows and elements that may be provided to theclinician to facilitate the input of selections and commands relevant tothe display of respiratory data and to display such respiratory data inan orderly and informative way, as described herein.

The above-mentioned embodiments of one or more missed breath indicatordisplay screens, illustrated in FIG. 4, are not meant to provide anexclusive array of potential or possible embodiments. Indeed, some ofthe features and characteristics of the above embodiments may beinterchanged and combined to provide additional embodiments andconfigurations of the described graphical user interfaces. In addition,in keeping with the spirit of the present disclosure, features describedmay not be essential, but may be added or removed according to thedesires and needs of a clinician, hospital, clinic, or other entity orindividual.

FIG. 5 is a flow diagram illustrating an embodiment of a method 500 fordisplaying and/or updating the display of a missed breath indicator. Inan embodiment, the method 500 is performed by the missed breath module109 described in FIG. 1. As illustrated, the ventilator system duringthe method 500 starts ventilation as is described with respect tostarting ventilation in the above method 300. The method 500 furtherincludes a detect patient effort operation 506 and an effective triggerdetermination operation 508, which are the same as operations 306 and308, respectively, and a update missed breath indicator operation 512.During the effective trigger determination operation 508 if the patienteffort is determined to be effective the method 500 will return to thedetect patient effort operation 506. During the effective triggerdetermination operation 508 if the patient effort is determined to beineffective the method 500 will proceed to the update missed breathindicator operation 512.

The method 500 further includes the update missed breath indicatoroperation 512. The ventilator during the update missed breath indicatoroperation 512 displays a missed breath indicator for the ineffectivetrigger effort. In an embodiment, the ventilator during the updatemissed breath indicator operation 512 updates the display of a missedbreath indicator previously displayed for the ineffective triggereffort. The ventilator may store a sequential history of the missedbreath indicators provided. The missed breath module 211, or anothersuitable component and/or module, may archive missed breath indicatorsaccording to time, and may associate a time element with the missedbreath indicators. In the alternative, the monitoring modules 216-222may associate the missed breath indicators with a time element, or timestamp, before communicating data to the graphics module 226 and/or themissed breath module 211. In either case, missed breath indicators maybe archived in sequential order based on time, resulting in an archivedineffective indicator. In an embodiment, a missed breath is displayed asat least one of text, symbol, prompt, graphic, light, line, cursor,interactive element, indicator, or by another suitable form of graphicdisplay. In another embodiment the missed breath indicator displays amissed breath rate. This rate can be the number or an average of thenumber of missed breaths per time period, where the time period can bepredetermined, such as a minute, or input by the clinician. For example,a missed breath indicator displays the number of missed breaths in thelast minute. The average can be taken from a predetermined or inputnumber of values over a predetermined or input period of time. Forexample, a missed breath indicator displays a rate based on an averageof the last five values where each value represents the number of missedbreaths for that minute. In an embodiment, a missed breath indicatordisplays a percentage or ratio at least partially representative of themissed breaths. For example, if the number of delivered breaths as wellas the number of missed breaths are both known then a missed breathindicator representing a percentage or ratio of missed breaths per totalbreaths may be displayed where total breaths is the addition of missedbreaths and delivered breaths. In an embodiment, the missed breathindicator displays a total breath indicator where the total breathindicator at least partially represents the total breaths, where thetotal breaths are the addition of missed breaths and delivered breaths.Additionally, a missed breath indicator may be displayed to representthat missed breaths are being monitored. Further, a missed breathindicator may be displayed to represent settings for monitoring missedbreaths. For example, a missed breath indicator displays a prompt withadjustable elements representative of turning on and/or off the missedbreath monitoring as well as inhalation and exhalation trigger valuesfor missed breath monitoring using the first trigger detectionapplication. Indeed, data may be collected and displayed according toany suitable method.

FIG. 6 is a flow diagram illustrating an embodiment of a method 600 fordisplaying and/or updating the display of a missed breath indicator. Inan embodiment, the method 600 is performed by the missed breath module109 described in FIG. 1. As illustrated, the ventilator system duringthe method 600 starts ventilation as is described with respect tostarting ventilation in the above method 300. The method 600 furtherincludes a monitor ventilation operation 602, a detect patient effortoperation 604, a calculate missed breaths operation 608, and an updatemissed breath indicator operation 612. In an embodiment, the methodfurther includes an update counter operation 606.

The method 600 includes the monitor ventilation operation 602. Duringthe monitor ventilation operation 602 the ventilator monitorsrespiratory data with at least one sensor. In an embodiment, the atleast one sensor is similar to the sensors utilized by the monitoringmodules 216-222 as described above. In an embodiment, the respiratorydata includes at least one of a pressure, flow, volume, intrapleuralpressure, and/or any other data collected regarding the physicalcondition of the patient.

The method 600 further includes the detect patient effort operation 604.During the detect patient effort operation 604 the ventilator analyzesthe respiratory data with a first trigger detection application and asecond trigger detection application. Further, during the detect patienteffort operation 604 the ventilator detects patient inspiratory and/orexpiratory efforts with the first trigger detection application and thesecond trigger detection application. In an embodiment, the ventilatoruses at least two trigger detection applications to analyze themonitored respiratory data. As discussed above, a trigger detectionapplication is a hardware or software application that determines when apatient effort occurs based on a selected or predetermined spontaneousbreath type. The second, or active trigger detection application mayinclude Proportional Assist Ventilation (PAV), Volume Ventilation Plus(VV+), I:E SYNC, Pressure Support (PS), Volume Support (VS), AssistControl (AC), Volume Control (VC), Pressure Control (PC), AirwayPressure Release Ventilation (APRV), Continuous Positive Airway Pressure(CPAP), and BiLevel Positive Airway Pressure (BPAP). The active triggerdetection application may determine patient efforts based on monitoringrespiratory parameters such as but not limited to pressure and flow. Inone embodiment the first, or background trigger detection application isI:E SYNC. In this embodiment, the background trigger detectionapplication determines patient effort based on monitoring intrapleuralpressure.

During the detect patient effort operation 604 if a patient effort isnot detected by a trigger detection application, the method 600 willreturn to the monitor ventilation operation 602. During the detectpatient effort operation 604 if a patient effort is detected by atrigger detection application, the method 600 will proceed to thecalculate missed breaths operation 608. In an embodiment, during thedetect patient effort operation 604 if a patient effort is detected by atrigger detection application, the method 600 will proceed to the updatecounter operation 606.

The method 600 includes the calculate missed breaths operation 608. Inan embodiment, during the calculate missed breaths operation 608 theventilator calculates a missed breaths metric based on detected patientinspiratory and/or expiratory efforts by the first trigger detectionapplication and detected patient inspiratory and/or expiratory effortsby the second trigger detection application. A missed breaths metric isan equation, number, point in time, value, percentage, rate, ratio,relationship, or any other suitable representation of missed breaths. Inan embodiment, if the first trigger detection application detects apatient inspiratory and/or expiratory effort that is not within anexpected and reasonable time delay, such as 3 seconds or less, of apatient inspiratory and/or expiratory effort detected by the secondtrigger detection application, then a breath has been missed. Theventilator during the calculate missed breaths operation 608 may store asingle instance of a missed breath or a sequential history of the missedbreaths over a predetermined period of time or a period of time set by aclinician. In an embodiment, an equation or mathematical operation isused to determine if the first detected patient effort correlates withthe second detected patient effort.

In an embodiment, the ventilator during the calculate missed breathsoperation 608 calculates a missed breaths metric based on the at leastone counter. In this embodiment, the method 600 further includes theupdate counter operation 606. During the update counter operation 606the ventilator updates a counter with a sum of the detected patientinspiratory and/or expiratory efforts by the first trigger detectionapplication and a sum of the detected patient inspiratory and/orexpiratory efforts by the second trigger detection application. In anembodiment, at least two counters are used, where a first counter isupdated with a sum of the detected patient inspiratory and/or expiratoryefforts by the first trigger detection application and a second counteris updated with a sum of the detected patient inspiratory and/orexpiratory efforts by the second trigger detection application. In anembodiment, a single counter is used where a count of patientinspiratory and/or expiratory efforts detected with the first triggerdetection application is added to the counter and a count of patientinspiratory and/or expiratory efforts detected with the second triggerdetection application is subtracted from the counter. In anotherembodiment a mathematical model, or algorithm is used to calculate howpatient inspiratory and/or expiratory efforts detected with the first orsecond trigger detection applications update at least one counter. In anembodiment, the at least one counter is reset after a predeterminedamount of time or breath cycles, or in response to clinician input.

In an embodiment, a first counter represents a sum of patientinspiratory and/or expiratory efforts detected with a first triggerdetection application and a second counter represents a sum of patientinspiratory and/or expiratory efforts detected with a second triggerdetection application. The ventilator during the calculate missedbreaths operation 608 performs an algorithm or mathematical operation,such as subtracting the count of the second counter from the count ofthe first counter, with the two counters to calculate a missed breathsmetric. In an embodiment, the value of a counter represents a missedbreaths metric and no further algorithm or mathematical operation isneeded to calculate the missed breaths metric. In another embodiment, asingle counter is used and an algorithm or mathematical operation mustbe performed with the counter in order to calculate the missed breathsmetric. Indeed, the missed breaths metric may be calculated according toany suitable method.

The method 600 further includes the update missed breath indicatoroperation 612. The ventilator during the update missed breath indicatoroperation 612 displays a missed breath indicator based on the missedbreaths metric. In an embodiment, the ventilator during the updatemissed breath indicator operation 612 updates the display of apreviously displayed missed breath indicator based on the missed breathsmetric. The ventilator may store a sequential history of the missedbreath indicators provided. The missed breath module 211, or anothersuitable component and/or module, may archive missed breath indicatorsaccording to time, and may associate a time element with the missedbreath indicators. In the alternative, the monitoring modules 216-222may associate the missed breath indicators with a time element, or timestamp, before communicating data to the graphics module 226 and/or themissed breath module 211. In either case, missed breath indicators maybe archived in sequential order based on time, resulting in an archivedineffective indicator. In an embodiment, the missed breath indicator isdisplayed on top of a graphical representation of a respiratory signalsuch as, but not limited to, pressure and flow, at an appropriatetemporal location based on when the missed breath occurred. In anembodiment, a missed breath is displayed as at least one of text,symbol, prompt, graphic, light, line, cursor, interactive element,indicator, or by another suitable form of graphic display.

In another embodiment the missed breath indicator displays a missedbreath rate. This rate can be the number or an average of the number ofmissed breaths per time period, where the time period can bepredetermined, such as a minute, or input by the clinician. For example,a missed breath indicator displays the number of missed breaths in thelast minute. The average can be taken from a predetermined or inputnumber of values over a predetermined or input period of time. Forexample, a missed breath indicator displays a rate based on an averageof the last five values where each value represents the number of missedbreaths for that minute. In an embodiment, a missed breath indicatordisplays a percentage or ratio at least partially representative of themissed breaths. For example, if the number of delivered breaths as wellas the number of missed breaths are both known, then a missed breathindicator representing a percentage or ratio of missed breaths per totalbreaths may be displayed where total breaths is the addition of missedbreaths and delivered breaths. In an embodiment, the missed breathindicator displays a total breath indicator where the total breathindicator at least partially represents the total breaths, where thetotal breaths is the addition of missed breaths and delivered breaths.

Additionally, a missed breath indicator may be displayed to representthat missed breaths are being monitored. Further, a missed breathindicator may be displayed to represent settings for monitoring missedbreaths. For example, a missed breath indicator displays a prompt withadjustable elements representative of turning on and/or off the missedbreath monitoring as well as inhalation and exhalation trigger valuesfor missed breath monitoring using the first trigger detectionapplication. Indeed, data may be collected and displayed according toany suitable method.

In an embodiment, the method 600 following the update missed breathindicator operation 612 returns to the monitor ventilation operation602.

It will be clear that the systems and methods described herein are welladapted to attain the ends and advantages mentioned as well as thoseinherent therein. Those skilled in the art will recognize that themethods and systems within this specification may be implemented in manymanners and as such is not to be limited by the foregoing exemplifiedembodiments and examples. In other words, functional elements beingperformed by a single or multiple components, in various combinations ofhardware and software, and individual functions can be distributed amongsoftware applications at either the client or server level. In thisregard, any number of the features of the different embodimentsdescribed herein may be combined into one single embodiment andalternative embodiments having fewer than or more than all of thefeatures herein described are possible.

While various embodiments have been described for purposes of thisdisclosure, various changes and modifications may be made which are wellwithin the scope of the present invention. Numerous other changes may bemade which will readily suggest themselves to those skilled in the artand which are encompassed in the spirit of the disclosure and as definedin the appended claims.

What is claimed is:
 1. A method implemented by a ventilator fordetermining missed breaths, the method comprising: monitoringrespiratory data with at least one sensor; analyzing the respiratorydata with a first trigger detection application and a second triggerdetection application; detecting patient inspiratory efforts with thefirst trigger detection application and the second trigger detectionapplication; calculating a missed breaths metric based on detectedpatient inspiratory efforts by the first trigger detection applicationand detected patient inspiratory efforts by the second trigger detectionapplication; and displaying a missed breath indicator based on themissed breaths metric.
 2. The method according to claim 1, wherein thefirst trigger detection application monitors patient inspiratory effortsbased on at least intrapleural pressure.
 3. The method according toclaim 1, wherein the step of calculating the missed breaths metriccomprises: updating a counter with a sum of the detected patientinspiratory efforts by the first trigger detection application and a sumof the detected patient inspiratory efforts by the second triggerdetection application; determining a difference with the counter betweenthe sum of the detected patient inspiratory efforts by the first triggerdetection application and the sum of the detected patient inspiratoryefforts by the second trigger detection application; and calculating amissed breaths metric based on the difference.
 4. The method accordingto claim 1, wherein the step of calculating the missed breaths metriccomprises: updating a first counter with a sum of the detected patientinspiratory efforts by the first trigger detection application and asecond counter with a sum of the detected patient inspiratory efforts bythe second trigger detection application; determining a differencebetween the first counter and the second counter; and calculating themissed breaths metric based on the difference.
 5. The method accordingto claim 1, wherein the step of displaying the missed breath indicatorcomprises: determining a graphical representation of the respiratorydata; displaying the graphical representation; determining anappropriate position for the missed breaths metric on the graphicalrepresentation based on time; and displaying the missed breath indicatorbased on the missed breaths metric at the appropriate position on thegraphical representation.
 6. The method according to claim 1, whereinthe step of displaying the missed breath indicator comprises: archivinga plurality of missed breaths metrics during a time period; determiningan appropriate missed breath indicator based on the archived pluralityof missed breaths metrics; and displaying the missed breath indicator.7. The method according to claim 6, wherein the step of displaying themissed breath indicator comprises: determining a graphicalrepresentation of the respiratory data; displaying the graphicalrepresentation; determining an appropriate position on the graphicalrepresentation based on time for the archived plurality of missedbreaths metrics; and displaying the missed breath indicator at theappropriate position on the graphical representation.
 8. A graphicaluser interface for displaying respiratory data, the ventilatorconfigured with a computer having a user interface including thegraphical user interface for accepting commands and for displayingrespiratory data, the graphical user interface comprising: graphicalrepresentations of respiratory data; and a missed breath indicator. 9.The graphical user interface according to claim 8, further comprising: adelivered breath indicator on the graphical representation.
 10. Thegraphical user interface according to claim 8, wherein the missed breathindicator is based on detected patient inspiratory efforts frommonitoring intrapleural pressure.
 11. The graphical user interfaceaccording to claim 8, wherein the missed breath indicator is a cursor onthe graphical representation representing a temporal location of amissed breath.
 12. The graphical user interface according to claim 8,wherein the missed breath indicator is at least one of a rate and apercentage representing missed breaths per total breaths, wherein totalbreaths is the addition of missed breaths and delivered breaths.
 13. Aventilatory system for providing a graphical user interface foraccepting commands and for displaying respiratory data, comprising: atleast one display device; a missed breath module that determines missedbreaths based on a first trigger detection application; a ventilationmodule that determines ventilation of a patient based on a secondtrigger detection application; and at least one memory, communicativelycoupled to the at least one processor and containing instructions that,when executed by a processor of the ventilatory system, provide agraphical user interface on the at least one display, comprising: amissed breath indicator.
 14. The ventilatory system of claim 13, whereinthe first trigger detection application determines missed breaths basedon monitored intrapleural pressure.
 15. The ventilatory system of claim13, wherein the graphical user interface on the at least one displayfurther comprises: graphical representations of respiratory data,wherein the missed breath indicator is located on the graphicalrepresentation.
 16. The ventilatory system of claim 13, wherein themissed breath indicator includes an archived ineffective indicator. 17.A computer-readable medium having computer-executable instructions forperforming a method implemented by a ventilator for determining missedbreaths, the method comprising: repeatedly monitoring respiratory datawith at least one sensor; repeatedly analyzing the respiratory data witha first trigger detection application and a second trigger detectionapplication; repeatedly detecting patient inspiratory efforts with thefirst trigger detection application and the second trigger detectionapplication; repeatedly calculating a missed breaths metric based on theresults of the detection operation; and repeatedly displaying a missedbreath indicator based on the missed breaths metric.
 18. A medicalventilator system, comprising: means for monitoring respiratory datawith at least one sensor; means for analyzing the respiratory data witha first trigger detection application and a second trigger detectionapplication; means for detecting patient inspiratory efforts with thefirst trigger detection application and the second trigger detectionapplication; means for calculating a missed breaths metric based on theresults of the detection operation; and means for displaying a missedbreath indicator based on the missed breaths metric.
 19. A methodimplemented by a ventilator for displaying respiratory data on agraphical user interface, the method comprising: detecting patientefforts with a first trigger detection application and a second triggerdetection application; determining an ineffective trigger effort by thepatient based on detected patient efforts by the first trigger detectionapplication not correlating with detected patient efforts by the secondtrigger detection application; and displaying a missed breath indicatorfor the ineffective trigger effort.
 20. The method according to claim19, wherein the first trigger detection application monitors patientefforts based on at least intrapleural pressure.
 21. The methodaccording to claim 19, wherein the step of displaying the missed breathindicator comprises: archiving a plurality of ineffective triggerefforts during a time period; determining an appropriate archivedineffective indicator for the archived plurality of ineffective triggerefforts; and displaying the appropriate archived ineffective indicatorfor the archived plurality of ineffective trigger efforts.
 22. Themethod according to claim 19, wherein the step of displaying the missedbreath indicator comprises: archiving a plurality of ineffective triggerefforts and effective trigger efforts during a time period resulting inan archived plurality of total trigger efforts; determining anappropriate archived total indicator for the archived plurality of totaltrigger efforts; and displaying the appropriate archived total indicatorfor the archived plurality of total trigger efforts.